Prime Minister David Cameron has insisted that his Government's plans to scrap child benefit for high-earners were "fair".
The change, announced by Chancellor George Osborne, applies to individuals earning £44,000 or more, but sparked controversy because it favours two-income households where both parents earn less than the threshold over families where one parent stays at home to look after the children.
A respected economic think-tank judged that some people would see this as unfair and warned that the move would "seriously distort" work incentives.
And Labour claimed the policy was "unravelling" after minister Tim Loughton suggested that the thresholds might need revising to iron out anomalies.
Mr Cameron insisted that changing the system to make it apply to household incomes, rather than individuals' pay, would require "an incredibly complicated means-testing system of bureaucracy for every family in the country", which he said would not be popular.
He said: "I do accept that this is a difficult decision, it is a tough decision, but I think it is fair to ask families who are better off to make a bigger contribution to dealing with the deficit so we can protect the poorest and most vulnerable people in our country.
"Under this change, child benefit will go on being paid to the 85 per cent of people who don't pay top-rate tax, and I think that is fair and right."
But within hours, an analysis by the Institute for Fiscal Studies (IFS) said some may regard the measure as "unfair" because it favours two-income families over those where one parent stays at home to look after children.
The IFS drew attention to consequences of the measures, which will mean a one-earner family with an income of £45,000 losing all its child benefit while a much better-off couple with an income of £40,000 each would keep the money. And it pointed out that a parent of two children with an income of £43,875 would actually lose money if given a pay rise of less than £2,975.
Mr Cameron told ITV's Daybreak: "Obviously we have this situation in the tax system itself. If you have one person earning £50,000, they pay top-rate tax, whereas if you have two people earning £25,000 they don't. This isn't a new principle."
Prime Minister David Cameron has insisted that his Government's plans to scrap child benefit for high-earners were "fair".
The change, announced by Chancellor George Osborne, applies to individuals earning £44,000 or more, but sparked controversy because it favours two-income households where both parents earn less than the threshold over families where one parent stays at home to look after the children.
A respected economic think-tank judged that some people would see this as unfair and warned that the move would "seriously distort" work incentives.
And Labour claimed the policy was "unravelling" after minister Tim Loughton suggested that the thresholds might need revising to iron out anomalies.
Mr Cameron insisted that changing the system to make it apply to household incomes, rather than individuals' pay, would require "an incredibly complicated means-testing system of bureaucracy for every family in the country", which he said would not be popular.
He said: "I do accept that this is a difficult decision, it is a tough decision, but I think it is fair to ask families who are better off to make a bigger contribution to dealing with the deficit so we can protect the poorest and most vulnerable people in our country.
"Under this change, child benefit will go on being paid to the 85 per cent of people who don't pay top-rate tax, and I think that is fair and right."
But within hours, an analysis by the Institute for Fiscal Studies (IFS) said some may regard the measure as "unfair" because it favours two-income families over those where one parent stays at home to look after children.
The IFS drew attention to consequences of the measures, which will mean a one-earner family with an income of £45,000 losing all its child benefit while a much better-off couple with an income of £40,000 each would keep the money. And it pointed out that a parent of two children with an income of £43,875 would actually lose money if given a pay rise of less than £2,975.
Mr Cameron told ITV's Daybreak: "Obviously we have this situation in the tax system itself. If you have one person earning £50,000, they pay top-rate tax, whereas if you have two people earning £25,000 they don't. This isn't a new principle."